scholarly journals Regulation of measles virus gene expression by P protein coiled-coil properties

2019 ◽  
Vol 5 (5) ◽  
pp. eaaw3702 ◽  
Author(s):  
Louis-Marie Bloyet ◽  
Antoine Schramm ◽  
Carine Lazert ◽  
Bertrand Raynal ◽  
Maggy Hologne ◽  
...  
Keyword(s):  
Gene Expression ◽  
Measles Virus ◽  
Narrow Range ◽  
Rna Viruses ◽  
Coiled Coil ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Large Protein ◽  
P Protein ◽  
Hydrophobic Anchor

The polymerase of negative-stranded RNA viruses consists of the large protein (L) and the phosphoprotein (P), the latter serving both as a chaperon and a cofactor for L. We mapped within measles virus (MeV) P the regions responsible for binding and stabilizing L and showed that the coiled-coil multimerization domain (MD) of P is required for gene expression. MeV MD is kinked as a result of the presence of a stammer. Both restoration of the heptad regularity and displacement of the stammer strongly decrease or abrogate activity in a minigenome assay. By contrast, P activity is rather tolerant of substitutions within the stammer. Single substitutions at the “a” or “d” hydrophobic anchor positions with residues of variable hydrophobicity revealed that P functionality requires a narrow range of cohesiveness of its MD. Results collectively indicate that, beyond merely ensuring P oligomerization, the MD finely tunes viral gene expression through its cohesiveness.

scholarly journals Norovirus gene expression and replication

2014 ◽  
Vol 95 (2) ◽  
pp. 278-291 ◽  
Author(s):  
Lucy G. Thorne ◽  
Ian G. Goodfellow
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Rna Viruses ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Genome Replication ◽  
Murine Norovirus ◽  
Technological Advances ◽  
Viral Genome Replication ◽  
Cell Processes

Noroviruses are small, positive-sense RNA viruses within the family Caliciviridae, and are now accepted widely as a major cause of acute gastroenteritis in both developed and developing countries. Despite their impact, our understanding of the life cycle of noroviruses has lagged behind that of other RNA viruses due to the inability to culture human noroviruses (HuNVs). Our knowledge of norovirus biology has improved significantly over the past decade as a result of numerous technological advances. The use of a HuNV replicon, improved biochemical and cell-based assays, combined with the discovery of a murine norovirus capable of replication in cell culture, has improved greatly our understanding of the molecular mechanisms of norovirus genome translation and replication, as well as the interaction with host cell processes. In this review, the current state of knowledge of the intracellular life of noroviruses is discussed with particular emphasis on the mechanisms of viral gene expression and viral genome replication.

scholarly journals A Single Amino Acid Residue Change in the P Protein of Parainfluenza Virus 5 Elevates Viral Gene Expression

2008 ◽  
Vol 82 (18) ◽  
pp. 9123-9133 ◽  
Author(s):  
Khalid A. Timani ◽  
Dengyun Sun ◽  
Minghao Sun ◽  
Celia Keim ◽  
Yuan Lin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Amino Acid Residue ◽  
Viral Gene Expression ◽  
Viral Rna ◽  
Single Amino Acid ◽  
Viral Gene ◽  
Wild Type ◽  
V Protein ◽  
P Protein

ABSTRACT Parainfluenza virus 5 (PIV5) is a prototypical paramyxovirus. The V/P gene of PIV5 encodes two mRNA species through a process of pseudotemplated insertion of two G residues at a specific site during transcription, resulting in two viral proteins, V and P, whose N termini of 164 amino acid residues are identical. Previously it was reported that mutating six amino acid residues within this identical region results in a recombinant PIV5 (rPIV5-CPI−) that exhibits elevated viral protein expression and induces production of cytokines, such as beta interferon and interleukin 6. Because the six mutations correspond to the shared region of the V protein and the P protein, it is not clear whether the phenotypes associated with rPIV5-CPI− are due to mutations in the P protein and/or mutations in the V protein. To address this question, we used a minigenome system and recombinant viruses to study the effects of mutations on the functions of the P and V proteins. We found that the P protein with six amino acid residue changes (Pcpi−) was more efficient than wild-type P in facilitating replication of viral RNA, while the V protein with six amino acid residue changes (Vcpi−) still inhibits minigenome replication as does the wild-type V protein. These results indicate that elevated viral gene expression in rPIV5-CPI− virus-infected cells can be attributed to a P protein with an increased ability to facilitate viral RNA synthesis. Furthermore, we found that a single amino acid residue change at position 157 of the P protein from Ser (the residue in the wild-type P protein) to Phe (the residue in Pcpi−) is sufficient for elevated viral gene expression. Using mass spectrometry and 33P labeling, we found that residue S157 of the P protein is phosphorylated. Based on these results, we propose that phosphorylation of the P protein at residue 157 plays an important role in regulating viral RNA replication.

scholarly journals Vesicular Stomatitis Virus Phosphoprotein Dimerization Domain Is Dispensable for Virus Growth

2019 ◽  
Vol 94 (6) ◽  
Author(s):  
Francine C. A. Gérard ◽  
Marc Jamin ◽  
Martin Blackledge ◽  
Danielle Blondel ◽  
Jean-Marie Bourhis
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Rna Viruses ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Dimerization Domain ◽  
Virus Growth ◽  
Intrinsically Disordered ◽  
P Protein ◽  
Vesicular Stomatitis ◽  
Negative Sense

ABSTRACT The phosphoprotein (P) of the nonsegmented negative-sense RNA viruses is a multimeric modular protein that is essential for RNA transcription and replication. Despite great variability in length and sequence, the architecture of this protein is conserved among the different viral families, with a long N-terminal intrinsically disordered region comprising a nucleoprotein chaperone module, a central multimerization domain (PMD), connected by a disordered linker to a C-terminal nucleocapsid-binding domain. The P protein of vesicular stomatitis virus (VSV) forms dimers, and here we investigate the importance of its dimerization domain, PMD, for viral gene expression and virus growth. A truncated P protein lacking the central dimerization domain (PΔMD) loses its ability to form dimers both in vitro and in a yeast two-hybrid system but conserves its ability to bind N. In a minireplicon system, the truncated monomeric protein performs almost as well as the full-length dimeric protein, while a recombinant virus harboring the same truncation in the P protein has been rescued and follows replication kinetics similar to those seen with the wild-type virus, showing that the dimerization domain of P is dispensable for viral gene expression and virus replication in cell culture. Because RNA viruses have high mutation rates, it is unlikely that a structured domain such as a VSV dimerization domain would persist in the absence of a function(s), but our work indicates that it is not required for the functioning of the RNA polymerase machinery or for the assembly of new viruses. IMPORTANCE The phosphoprotein (P) is an essential and conserved component of all nonsegmented negative-sense RNA viruses, including some major human pathogens (e.g., rabies virus, measles virus, respiratory syncytial virus [RSV], Ebola virus, and Nipah virus). P is a modular protein with intrinsically disordered regions and folded domains that plays specific and similar roles in the replication of the different viruses and, in some cases, hijacks cell components to the advantage of the virus and is involved in immune evasion. All P proteins are multimeric, but the role of this multimerization is still unclear. Here, we demonstrate that the dimerization domain of VSV P is dispensable for the expression of virally encoded proteins and for virus growth in cell culture. This provides new insights into and raises questions about the functioning of the RNA-synthesizing machinery of the nonsegmented negative-sense RNA viruses.

scholarly journals Measles Viruses Possessing the Polymerase Protein Genes of the Edmonston Vaccine Strain Exhibit Attenuated Gene Expression and Growth in Cultured Cells and SLAM Knock-In Mice

2008 ◽  
Vol 82 (23) ◽  
pp. 11979-11984 ◽  
Author(s):  
Makoto Takeda ◽  
Shinji Ohno ◽  
Maino Tahara ◽  
Hiroki Takeuchi ◽  
Yuta Shirogane ◽  
...  
Keyword(s):  
Gene Expression ◽  
Measles Virus ◽  
Cultured Cells ◽  
Lymphocyte Activation ◽  
Viral Gene Expression ◽  
Promoter Sequence ◽  
Virus Genome ◽  
Viral Gene ◽  
Wild Type ◽  
Vaccine Type

ABSTRACT Live attenuated vaccines against measles have been developed through adaptation of clinical isolates of measles virus (MV) in various cultured cells. Analyses using recombinant MVs with chimeric genomes between wild-type and Edmonston vaccine strains indicated that viruses possessing the polymerase protein genes of the Edmonston strain exhibited attenuated viral gene expression and growth in cultured cells as well as in mice expressing an MV receptor, signaling lymphocyte activation molecule, regardless of whether the virus genome had the wild-type or vaccine-type promoter sequence. These data demonstrate that the polymerase protein genes of the Edmonston strain contribute to its attenuated phenotype.

scholarly journals Immunological Effects and Viral Gene Expression Determine the Efficacy of Oncolytic Measles Vaccines Encoding IL-12 or IL-15 Agonists

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 914 ◽  
Author(s):  
Backhaus ◽  
Veinalde ◽  
Hartmann ◽  
Dunder ◽  
Jeworowski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fusion Protein ◽  
Therapeutic Efficacy ◽  
Measles Virus ◽  
Nk Cell ◽  
Viral Gene Expression ◽  
Interleukin 12 ◽  
Viral Gene ◽  
Interleukin 15

Tumor-targeted immunomodulation using oncolytic viral vectors is currently being investigated as a promising strategy in cancer therapy. In a previous study, we showed that a measles virus Schwarz vaccine strain (MeVac) vector encoding an interleukin-12 fusion protein (FmIL-12) is an effective immunotherapy in the MC38cea murine colon adenocarcinoma model. We hypothesized that MeVac encoding interleukin-15 may mediate enhanced T and NK cell responses and thus increase the therapeutic efficacy, especially in NK cell-controlled tumors. Therefore, we generated MeVac vectors encoding an interleukin-15 superagonist, FmIL-15. Replication and oncolytic capacity, transgene expression, and functionality of MeVac FmIL-15 vectors were validated in vitro. Effects on the tumor immune landscape and therapeutic efficacy of both FmIL-12 and FmIL-15 vectors were studied in the MC38cea and B16hCD46 tumor models. Treatment with MeVac FmIL-15 increased T and NK cell infiltration in both models. However, MeVac FmIL-12 showed more robust viral gene expression and immune activation, resulting in superior anti-tumor efficacy. Based on these results, MeVac encoding a human IL-12 fusion protein was developed for future clinical translation.

scholarly journals Latency Reversing Agents: Kick and Kill of HTLV-1?

2021 ◽  
Vol 22 (11) ◽  
pp. 5545
Author(s):  
Annika P. Schnell ◽  
Stephan Kohrt ◽  
Andrea K. Thoma-Kress
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Viral Gene Expression ◽  
Cytotoxic T Cell ◽  
Viral Gene ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Reversing Agents ◽  
Ctl Responses

Human T-cell leukemia virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), is a retrovirus, which integrates into the host genome and persistently infects CD4+ T-cells. Virus propagation is stimulated by (1) clonal expansion of infected cells and (2) de novo infection. Viral gene expression is induced by the transactivator protein Tax, which recruits host factors like positive transcription elongation factor b (P-TEFb) to the viral promoter. Since HTLV-1 gene expression is repressed in vivo by viral, cellular, and epigenetic mechanisms in late phases of infection, HTLV-1 avoids an efficient CD8+ cytotoxic T-cell (CTL) response directed against the immunodominant viral Tax antigen. Hence, therapeutic strategies using latency reversing agents (LRAs) sought to transiently activate viral gene expression and antigen presentation of Tax to enhance CTL responses towards HTLV-1, and thus, to expose the latent HTLV-1 reservoir to immune destruction. Here, we review strategies that aimed at enhancing Tax expression and Tax-specific CTL responses to interfere with HTLV-1 latency. Further, we provide an overview of LRAs including (1) histone deacetylase inhibitors (HDACi) and (2) activators of P-TEFb, that have mainly been studied in context of human immunodeficiency virus (HIV), but which may also be powerful in the context of HTLV-1.

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